1. Technical Field
The present disclosure relates generally to electrosurgical systems that utilize energy to perform electrosurgical procedures. More particularly, the present disclosure is directed to a switching power supply for an electrosurgical generator having a lossless current sense circuit.
2. Description of the Related Art
Electrosurgical generators are employed by surgeons in conjunction with an electrosurgical instrument to cut, coagulate, desiccate and/or seal patient tissue. High frequency electrical energy, e.g., radio frequency (RE) energy, is produced by the electrosurgical generator and applied to the tissue by the electrosurgical tool. Both monopolar and bipolar configurations are commonly used during electrosurgical procedures.
Electrosurgical techniques and instruments can be used to coagulate small diameter blood vessels or to seal large diameter vessels or tissue, e.g., soft tissue structures, such as lung, brain and intestine. A surgeon can either cauterize, coagulate/desiccate and/or simply reduce or slow bleeding, by controlling the intensity, frequency and duration of the electrosurgical energy applied between the electrodes and through the tissue. In order to achieve one of these desired surgical effects without causing unwanted charring of tissue at the surgical site or causing possible damage to adjacent tissue, e.g., thermal spread, it is necessary to control the output from the electrosurgical generator, e.g., power, waveform, voltage, current, pulse rate, etc.
Energy is supplied to the electrode(s) by an electrosurgical generator coupled thereto. The electrosurgical generator may include a switched inductor system to provide an RF output to the electrode(s). Switched inductor systems utilize at least one switch, at least one diode and at least one inductor. As better low loss inductor elements are produced, it gets harder to measure the current through the inductor without considerable additional circuitry. The additional circuitry adds components, size and power consumption to a final product thereby negating the benefit of having a lossless detection method.